A method of forming an image including print information and an optical diffraction structure is widely known as a security countermeasure against falsification of information. For the image forming method, there is known a method of transferring a layer in which the optical diffraction structure of an optical diffraction structure transfer sheet to predetermined information on a transfer object after the predetermined information is printed on the transfer object (For example, see Patent Document 1).
Patent Document: Japanese Patent Laid-Open No. 8-118857